Sounds like the tub full of cold water and sugar helps. I don't want to advise you per se, for risk of your dogs health but have you just tried to give her sugar before without the cold water? It might be helpful to eliminate all the unkowns if you did one test at a time. If you only give her sugar and it helps then it could be hypoglycemia. Our black GSP gets weak on hotter hunts....even on mild hunts sometimes so we give him sugar cubes and it helps. I'm not a vet but giving her a multitude of treatments at once might make it even more difficult to figure out.